The storage of gaseous hydrogen at high pressures is particularly important for its use in automobiles. In addition, in this application in particular, the relative rapidness with which a tank is filled is an important factor. Specifically, the operation of filling hydrogen tanks on board vehicles having a fuel cell or an internal combustion engine operating on hydrogen must be able to be carried out in at most a few minutes. The filling must be carefully controlled since rapid pressurization of the gas causes heating, which may become incompatible with the constituent material of the tank (for example temperatures above 85° C.).
To solve this problem, one solution consists of controlling the rate of filling according to the temperature of the gas in the tank. However, this solution has the drawback of lengthening the time to fill the tank.
Another solution consists of providing a refrigeration unit in the filling station. However, this solution requires substantial and costly infrastructures, in particular in terms of electrical energy. Specifically, according to that method, the gas is precooled before it enters the tank, typically down to temperatures of between −45° C. and 0° C. in order to prevent the upper limit of the temperature operating range of this tank from being reached during filling. In this regard, the reader may refer to the document FR 2 891 347 A1 which describes an inexpensive solution for carrying out this precooling.
To effect the precooling, the general practice is to use a heat exchanger cooled by a cold source such as a bath of glycol-water solution or of liquid nitrogen. However, in certain situations, precooling the pressurized gas is difficult to control at low cost. This is because, owing to the variations in instantaneous heat exchange power, instabilities in the temperature of the cooled pressurized gas are observed. Moreover, the known heat exchange means are relatively bulky.
Accordingly, there is a need for a device/method which alleviates all or some of the drawbacks of the prior art mentioned above.